THE CRANE-FLIES OF NEW YORK PART II 711 



motion, partly flying and partly walking, over the ground or up the trunks 

 of trees. This habit is discussed under the account of Tipula taughannock 

 (p.*1013), and has been observed in other woodland-inhabiting species of 

 this genus as T. macrolabis, T. fuliginosa, T. fragilis, and others. In 

 T. fragilis, when a male comes upon a pair already in copula he passes 

 on without interrupting them. Somewhat similar mating habits are found 

 in some species of Dicranomyia (D. trinotata, D. badia, and D. simulans), 

 Discobola, Antocha, Chionea, Dactylolabis montana, some Pediciini as 

 Dicranota, and the Cylindrotominae. 



Many crane-flies have developed swarming habits for the purpose of 

 mating, these including representatives of most of the tribes of the 

 Limnobiinae and a few tipuline forms. Dicranomyia morioides was 

 observed by Needham (1908 a: 204) swarming in vast numbers near 

 Ithaca, New York, but here the swarms consisted only of males. Like- 

 wise, Erioptera armata (Needham, 1908 a: 206) was found swarming near 

 Lake Forest, Illinois; but, out of several hundred individuals captured, 

 all except three were males. The writer has observed swarming in numer- 

 ous species of Ormosia, Molophilus, Erioptera, Gonomyia, Rhabdomastix, 

 Limnophila, Ula, Epiphragma, Eriocera, Dicranota, Rhaphidolabis, 

 Trichocera, and other genera, and here, too, the males were always 

 predominant. The specific data may be consulted under these various 

 headings. The males of Dicranota swarm in rather large numbers pre- 

 liminary to searching for the females, which rest quietly on the branches 

 of neighboring shrubbery. Limnophila ultima, as noted at Gloversville, 

 New York, on September 7, 1916, was swarming at half past six o'clock 

 in the evening. The swarms here consisted of from fifty to sixty individuals 

 and took place from ten to eighteen feet above the earth. Mating took 

 place frequently in the air, and as soon as a pair were in copula they flew 

 away to some point to rest, many pairs being observed hanging on a 

 clothesline a few feet away. There were three distinct swarms, which 

 showed little tendency to fuse altho their flight area was very close. The 

 vast swarms of Eriocera longicornis and of Trichocera are mentioned or 

 discussed elsewhere in this paper. When pairs are in copula, they readily 

 take flight, still united, the female usually trailing the male after her; 

 altho in a few groups, in which the male is the larger individual of the 

 two, the situation is the opposite. Brachypremna, the familiar " weaver " 

 of the Southern States, has a very remarkable vertical dance of several 



